Brucellosis is a re-emerging zoonotic disease that affects humans and a variety of farm animals. As well as a threat to public health it has considerable economic importance. The etiologic agent responsible for human infection, Brucella melitensis, is classified by both NIAID and CDC as a Category B biothreat pathogen. Antibiotics are only partially effective at controlling the disease and there is no vaccine approved for use in humans. Thus, prompt and accurate diagnosis is the key to containing infection. Currently, the most common diagnostic tests for Brucella are based on indirect serology which are lacking in specificity and sensitivity as well as speed of execution. Thus, there is a pressing need to develop improved diagnostics, especially technologies that may be used at field level. This investigation proposes to address this issue and develop a superior and robust technique for diagnosing Brucella infection with highly specific, non-cross reactive antibody reactions. We will achieve this goal by screening the Brucella genome using novel proteomic chip technology to identify unique antigens that will yield highly specific and accurate diagnoses. This work will be undertaken in Phase 1 of the application. In Phase 2, when antigens have been selected, we anticipate that we will proceed to develop ELISA and immunoblot assays. In parallel, both ELISA and lateral flow "dipstick" tests for Brucella antigen will be constructed. We envisage that the antigen assays will have particular utility in detecting Brucella disseminated in the context of the bioterrorism event. The diagnostic tools developed within this application will be rigorously evaluated for sensitivity and specificity using large and diverse panels of human and animal Brucella-positive sera available through our collaborators. The project proposes to develop a highly sensitive and robust diagnostic test for brucellosis, also known as "undulant fever", an infectious disease that causes serious illness in farm animals and humans. The current techniques for diagnosing infection are somewhat unreliable and based on outmoded methods. This investigation will use state- of-the-art technology to identify new structures or antigens on Brucella bacteria that may be used to develop a test with superior diagnostic performance. [unreadable] [unreadable] [unreadable]